Holston_River_Rambler

6z Euro manages to look kind of RGEMish and gets some qgf back over the mts: How much of that makes it to the ground is up in the air. It is a slight west jog from 0z.

Not that anybody trusts the Euro at this point, but for those of use who are happy just to se snow falling, it gets the job done tomorrow AM for parts of East TN, SW VA and SE KY even the 6z GFS is trying: The only other models that are trying to show this are the WRF-ARWs, so it is what it is I guess.

This may have been the little piece of vorticity John was talking about, but I'm not sure, so here is a frame from the 6z RGEM: Look at that tiny area of vorticity in the blue circle. Now watch what it does as the run progresses: It seems to be encouraging at least some part of the southern vort to interact with the northern one. It's a pretty subtle strand of vorticity, so something to watch on the very Hi Res models over the next few cycles.

I think I saw someone ask this in one of the other forum areas. They said to turn your phone sideways and for some reason that would show the location when it doesn't if your phone is vertical. Give that a try and see if it works. i ay be misremembering that though so if that is the case, apologies.

It looked to me like there was the potential for a little more interaction early on, but that didn't work out at all. One positive note is that there has been a noticeable, but small trend with the jet streak to become stronger and move NW over the past few runs: We're pretty well positioned to be on the right entrance region if that amplification continues.

I think the GFS is going to be a tick better this run, based on vorticity changes at hr 51, but let's see how it plays out.

I've figured it out. We've run out of thunder. TIMs model needs a reboot tomorrow night.

You forgot that at the end of the run we got the ever fruitful Miller B to cap it off. <please read with sarcasm>

I wonder if this ends up being like the December 2017 storm?

That being said, I agree with John, but the worst we can expect now is a last minute NW trend to help extreme eastern areas.

But if i lived in the NC Triad area, I wouldn't get my hopes up and claim the GFS has saved the day: People talk about warning shots, IMO if I lived in the Raleigh Durham area, these are warning shots:

12z Euro hates the eastern Great Valley and wants it to suffer:

If we can get the GFS to do this with the weekend (and that is a big IF, we can't jinx it by saying it is a done deal), we should be good: again we just don't want it too NW, lol. The 6z was slightly NW of what John noted at 0z. If that trend continues, I should be able to make a nice gif showing it by 18z. 6z GEFS already seems to have some members with a Euro like solution: 6z GEFS members:

18z Euro looks pretty similar to 12z wrt the weekend storm at least out to hour 90 at the end of its run.

If we want snow, here's how we want the long range AFDs to go through Friday AM: ~3 AM 1/18: Generally followed the WPC guidance which pushes the arctic front far enough south to have little impact from overrunning precip, broad-brushed a few hundreths of an inch of precip. over the mountain counties since ensemble means hint at this possibility ~330 PM 1/18: Afternoon guidance continues to flip/flop considering a late week/ weekend system. The 0z deterministic ECMWF had been showing more amplitude with this shortwave, but 12z guidance has come more in line with the deterministic GFS which keeps all the precip over the mountains and in the Carolinas ~335 AM 1/19: Overnight ensemble means have trended a bit westward with moisture, but any impacts are several days away, so generally populated the grids with 20% chance of wintry mix in the valleys and snow in the higher elevations ~315 PM 1/19: models continue to struggle with a fast flow progressive pattern. Several runs of both the deterministic GFS and ECMWF had been showing a rather strung out strand of vorticity riding a boundary along approximately I-20, but the GFS now shows a 999mb surface lp over Macon while the ECMWF has trended towards the GFS's solution. Based on poor run-to-run consistency, stuck with a broad 20 -30% chance of snow in the eastern zones, transitioning to rain during the day in the lower elevations ~4 AM 1/20: Ensemble means continue to suggest a more robust shortwave is possible into the weekend, but won't make many drastic changes to the forecast based on a single suite of NWP data. ~358 PM 1/20: Big changes to the forecast as deterministic guidance argues that a strong shortwave dropping in from the N high Plains races in to partially phase with some southern stream energy over TX. CMC, GFS, and ECMWF all have similar solutions, but minor differences in track of the slp result in major forecast headaches. CMC is the coldest and thus the snowiest, but since this is a known bias of that model, its solution was only weighted slightly in forecast means. Regardless of the track, all global deterministic guidance suggests ample isentropic ascent and positive vorticity advection would produce precip., much of it of a wintry nature. To avoid confusion with other forecast offices, followed the NMB for any snowfall accumulation. Will leave any WWX products for future shifts. I in no way mean this as a dig at the NWS AFDs. I love reading them and hopefully I kind of got the tone right. Imitation is the sincerest form of flattery. It was interesting coming up with stuff to write though, lol. I can see why some of the offices are having a little more fun with them now (I'm looking at you BNA). But let's be real East Tennesseeans, I don't know if it is a curse or what, but I have never seen a storm happen, when any pros were honking on it at this distance. I literally won't tell my wife if I think there is something coming, because of jinx fear. Back in the realm of actual pattern discussion, the GFS continues the trend NW with the Thursday system and the two shortwaves in question for the weekend are inching closer together at 18z.

His Grace the Euro trying to tease us:

12z Euro looked nice for this weekend: Just don't want it to end up too far NW, lol.

Ehhh never mind, false aleet. I saw this and got all excited but no dice: The southwest shortwave kicks out too quickly. It was close though:

I think the CMC is going to barely miss having a big phased storm early to mid next week.

12z was a little bit south with the weekend storm, but there was a big boom potential on that run too. Imagine if the secondary vort. doesn't sink SSW and get cut off. If that one catches the southern one and then the third one catches em both, boom.

It may not be a hit this run, but it is hard not like the overall look for this weekend: Northern steam energy, southern stream energy and an extra kick of moisture from the eastern Pac:

Checks out with the 12z GFS:

End of the 12z RGEM looks pretty nice for a possible overrunning event.:

Made a gif of the IR satellite of the storm:

6z Euro had the wave "riding the front" snow over SE KY and SW VA that I think we've seen on most of the recent model runs, but it also tried to build another wave back over MS toward the end: I don't know what I think about this weekend system. Do y'all think this is a typical situation where we can expect a NW trend? If that's the case I like where we are at this range.